Bicycle gearing



Oct. 6, 1931. E. MURASE 1,826,565

BI CYCLE GEARING Filed May 5, 1950 2 Sheets-Sheet EN TOR.

f/mfl/ Mae/$5 Oct. 6, 1931. E. MURASE BICYCLE GEARING Filed May 3, 1930 2 Sheets-Sheet 2 N\ m M N N w N N w fl 1 w.- r' A y n x J TTORNEYS.

I Patented ()ct. 6 1931 TES umreo sr BICYCLE application filed May 3,

This invention'relates to improvements in bicycle gearing and has particular reference to means for changing the speed ratio of the driving of the bicycle. p j

The principal object of this invention is to produce a gear shifting arrangement which 'may be incorporated in .the usual coaster brake hub of a bicycle whereby the user of V numerals are employed to designate like parts throughout the same, J a Figure I is a top plan view of my gearing arrangement as the same would apply to a bicycle, a portion ofwhich is shown broken away,

Figure II is a cross sectional view taken on the line 2-2 of Figure I, and T Figure III is a cross sectional auxiliary hub.

The ordinary bicycle has incorporated in the rear hub what is commonly termed a coaster brake, the arrangement being such that when the operator is pedaling in forward direction, motion is transmitted to the hub for the purpose of rotating the same and when the operator stops pedaling the hub is free view of the to rotate. When the operator pushes back wardly upon the pedals a braking action is accomplished thus stopping the rotation of the hub and wheel attached thereto. Applicant has retained all of these features and has added thereto an arrangement whereby the speed ratio between the pedal sprocket and the hub may be changed. I

In the accompanying drawings wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 5 designates the customary axle which is held between the arms'6 and 7 of the frame and secured thereto through the mepart of this specificationand in which like PATENT, OFFICE nrrcnrmunasnfor sAnrnANcIsco, camrormm GEABING 1930. I Serial No. 449,589.

dium of nuts 8 and 9. i A hub shell is shown I;

at 11 which is the ordinary coaster brake shell and has the wheel rim secured thereto through the medium of the ordinary spokes 12. This shell is supported upon roller bearings 13 and 14, the roller bearing 13 bein interposed between the shell and a cone 1' which cone abuts a spacer 17 upon which is freely mounted a pair of discs 18 and 19.

The member 19 is held against rotation by its engagement with the cone 16. This cone is held by the usual coaster-brake arm 20, which arm connects to the frame 6, it being under stood that the cone 16 and the member 19 are held against rotation with respect to each other, in any convenient manner such as by providing the usual serrated surfaces commonly found in coaster brake constructure. One of these discs has cam shaped projections 21 which fit into correspondingly shaped.

thread 31 which is engaged by an internal; thread 32 formed upon the coupling member 33 which coupling member is free to slide and rotate upon the axle 5 the abutting surfaces of the cone'16 and disc 19 are serrated so as to prevent relative movement thereand a sprocket 38 will be hereafter known as the transfer sprocket. ,The sprocket 38 is secured to the sprocket 28 in any convenient manner. A second cone39 is interposed between thedriving sprocket and the arm 7.

The roller bearings serve to reduce the fric-- 7 device which will accomplish 'allthe obJeOts tion'loetw-een these points.

Mounted upon the frame sprocket46tsecliredto the other. part. Witlr 'in thi's shub;v is a similar couplingmember to that shown at 33 the action of which is so well known that further comment is unnecessary. A chain-$47 passes from; the

sprocket 44 to the'transfer sprocket 38.: The

i 1 main drive chain 48 passes from the pedal V sprocket over the maindrive sprocket 28 and .1. .low ratio;sprocket37' r g ,1 The result of; th .'constr-uction is that] whemmy device; is installed-zupon' a rbicycle a chain 49 passes from 'tliesprocket' 46 to the theerider pedals inthe usual mannerv with the result, that the ;chai-1r 48- transmits motion to I the; main drive sprocket 28,, the rotation of .Whicln througha the threaded connection. 31 I I, p p

- inga low. ratio sprocket attached thereto; of

7 iaird321drawstheicoupling member 33 against the: shell: 1].- at thepoint 36 and consequently rotationofithe;wheel'will result. 'The. other I 1 chains merely; runaidl'e- Y Whentheioperator encounters a grade and v wishes to changeto the lowgear ratio, he first stops p'edalling the result. that th'e coupling member wills-move. toward, the left of; the drawing; av su-flicientdistance tobrake the; driving; connection withtheshell. It mightbesaid that the'deviceis coastingarrangement;

- fil and; which is connected. to the lug 52:. car

;ried;' upon ;the-. member: 18, results. in moving the -members18 and, l9 'w -ith relationto each action; will. move-the-cha-in 148; which will rd 1 tate theamainjdrivingsprocket28 and transfer sprocket 38'attached thereto; This rotation of the transfer sprocket; will: cause, the -chain 471to=rotate the sprocket 44i1p0n the interior 05f thehub ofwhichnisa threadwhich member! are brackets 42 and 45 between which is posi By now pulling upona lever s conveniently? located upon the frame of the L I bicyclegc. which; lever is connected to the wire be taken as a preferred example of the same I and that various changes'relati've to the material size,.. shape', andiarrangementi of parts may be resorted to without departing from the spirit of the invention or the scope of the snbj'oined; claims;

Having thus described my invention, I

1. In combination with 'a'bicycle hub, of

- a low ratio'sprocliet' attachedthereto, a main drive.v sprocket freely rotatable with relation to said hub, means for locking 'saijd main drive sprocket tofsaid hub andll means "for holding said main drive: sprocket unlocked with respect to said';huh ion the purpose 85 specifiedii r a 2.. Incombination With a bicycle hub'havmovable in is said; hub and: being adapted to lock said main drive sprocket to said hub' and means for holding said coupling member whereby saidcoupling member'may be held out of locking arrangement fora predetermined interval; a V v 3. In combination with a bicycle hav-"" inga low ratio sprocket attached thereto, of a. main. drive sprocket, a coupling member movable in said. hub and being adaptedto lock said 'main drive sprocket to said hub, means for holding said coupling member whereby said couplingjmeinber maybe held out'oflocking arrangement when desired; said means including apai'r of'discs cam actuated, means for moving sald'discs apart, andja slide rod actuated by said discs for holdi 5 coupling member out 'iof' engagement with said hub; 1 v

In testimony whereof- I afiix' my signature.

EIIoHr'MURA-sn 1 H 3 engages'a'acouplingmember 5-4; The direc- 7 tiOH'EOf; the thread-Qis-suc-h thatthisvcoupling' memben will be drawn toward the sprocket44 a,andlthuslockthetwo halvesof-the sleeve 43 I SO} that they wi]l- .-rotate in unison and as a r consequence; the sprocket48 will-how trans thezhighgearratiom'ay.easily-berestored and 1 duringthe high gearconnectionthe diiierential actionbetween thechains 41 and. 49 takes place-due to theicoupling memberswithinthe splitihnb 43, ,breaking its hold. 

